xen-netback: Using a new state bit instead of carrier

This patch introduces a new state bit VIF_STATUS_CONNECTED to track whether the
vif is in a connected state. Using carrier will not work with the next patch
in this series, which aims to turn the carrier temporarily off if the guest
doesn't seem to be able to receive packets.

Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
v2:
- rename the bitshift type to "enum state_bit_shift" here, not in the next patch
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h
index 28c98229e95f66c9123fae82a0d3e453fd761b42..4a92fc19f410983d6695b311eecceb200c40f14f 100644 (file)
--- a/drivers/net/xen-netback/common.h
+++ b/drivers/net/xen-netback/common.h
@@ -198,6 +198,11 @@ struct xenvif_queue { /* Per-queue data for xenvif */
        struct xenvif_stats stats;
 };
 
+enum state_bit_shift {
+       /* This bit marks that the vif is connected */
+       VIF_STATUS_CONNECTED
+};
+
 struct xenvif {
        /* Unique identifier for this interface. */
        domid_t          domid;
@@ -220,6 +225,7 @@ struct xenvif {
         * frontend is rogue.
         */
        bool disabled;
+       unsigned long status;
 
        /* Queues */
        struct xenvif_queue *queues;

diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index bd59d9dbf27b1e11e049309745bed20b7d6e97a2..fbdadb3d8220828288783539e194e252b85f2b75 100644 (file)
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -55,7 +55,8 @@ static inline void xenvif_stop_queue(struct xenvif_queue *queue)
 
 int xenvif_schedulable(struct xenvif *vif)
 {
-       return netif_running(vif->dev) && netif_carrier_ok(vif->dev);
+       return netif_running(vif->dev) &&
+               test_bit(VIF_STATUS_CONNECTED, &vif->status);
 }
 
 static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id)
@@ -267,7 +268,7 @@ static void xenvif_down(struct xenvif *vif)
 static int xenvif_open(struct net_device *dev)
 {
        struct xenvif *vif = netdev_priv(dev);
-       if (netif_carrier_ok(dev))
+       if (test_bit(VIF_STATUS_CONNECTED, &vif->status))
                xenvif_up(vif);
        netif_tx_start_all_queues(dev);
        return 0;
@@ -276,7 +277,7 @@ static int xenvif_open(struct net_device *dev)
 static int xenvif_close(struct net_device *dev)
 {
        struct xenvif *vif = netdev_priv(dev);
-       if (netif_carrier_ok(dev))
+       if (test_bit(VIF_STATUS_CONNECTED, &vif->status))
                xenvif_down(vif);
        netif_tx_stop_all_queues(dev);
        return 0;
@@ -528,6 +529,7 @@ void xenvif_carrier_on(struct xenvif *vif)
        if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN)
                dev_set_mtu(vif->dev, ETH_DATA_LEN);
        netdev_update_features(vif->dev);
+       set_bit(VIF_STATUS_CONNECTED, &vif->status);
        netif_carrier_on(vif->dev);
        if (netif_running(vif->dev))
                xenvif_up(vif);
@@ -625,9 +627,11 @@ void xenvif_carrier_off(struct xenvif *vif)
        struct net_device *dev = vif->dev;
 
        rtnl_lock();
-       netif_carrier_off(dev); /* discard queued packets */
-       if (netif_running(dev))
-               xenvif_down(vif);
+       if (test_and_clear_bit(VIF_STATUS_CONNECTED, &vif->status)) {
+               netif_carrier_off(dev); /* discard queued packets */
+               if (netif_running(dev))
+                       xenvif_down(vif);
+       }
        rtnl_unlock();
 }
 
@@ -656,8 +660,7 @@ void xenvif_disconnect(struct xenvif *vif)
        unsigned int num_queues = vif->num_queues;
        unsigned int queue_index;
 
-       if (netif_carrier_ok(vif->dev))
-               xenvif_carrier_off(vif);
+       xenvif_carrier_off(vif);
 
        for (queue_index = 0; queue_index < num_queues; ++queue_index) {
                queue = &vif->queues[queue_index];

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 769e553d3f45dfc56a12caf39133dd9870fcb69c..6c4cc0f44da5ce506286ee36c061d62525a41689 100644 (file)
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -1953,7 +1953,7 @@ int xenvif_kthread_guest_rx(void *data)
                 * context so we defer it here, if this thread is
                 * associated with queue 0.
                 */
-               if (unlikely(queue->vif->disabled && netif_carrier_ok(queue->vif->dev) && queue->id == 0))
+               if (unlikely(queue->vif->disabled && queue->id == 0))
                        xenvif_carrier_off(queue->vif);
 
                if (kthread_should_stop())